Irrigations systems employ a plurality of valve stations that are distributed over a large area to be irrigated. Referring to FIG. 1A and FIG. 1B, an irrigation system 100 comprises valve stations 120 each of which is responsively connected with hotwires 115 to output ports 116, respectively, of a controller 110. Further, valve stations 120 are connected via a common wire 117 with an input port 119 of controller 110 to complete a corresponding control circuit 118 of irrigation system 100. Controller 110 controls the operation of valve stations 120 by sending over control circuit 118 a suitable signal over the respective hotwires 115 in accordance with, for example, a timer-function. For example, as is schematically illustrated in FIG. 1A, a first control signal S1 is provided over control circuit 118 at a given time T1 to alter the operational mode of first valve station 120A. Subsequently, (FIG. 1B) at a given time T2, another signal S2 instead of the previous signal S1 is sent over control circuit 118, thereby changing the operational mode of first valve station 120A to its initial mode, whilst subsequently changing the operational mode (e.g., from “close” to “open”) of second valve station 120B, and so forth. Similarly, third valve station 120C and fourth valve station 120D are subsequently operated, as is schematically illustrated in FIG. 2C and FIG. 2D. The above-outlined sequence may be performed sequentially for all valve stations 120 of irrigation system 100 in a loop, i.e., each valve station 120 may be addressed at least once during a working cycle.
U.S. Pat. No. 6,932,277, entitled “Sprinkler Valve Wiring Apparatus and Method” discloses an irrigation system comprising a plurality of valves designed to be electrically activated by a control unit. Valve wires extend from the valves to a junction unit. Control unit wires extend from the control unit to the junction unit, and are electrically coupled to the valve wires within the junction unit. The control unit wires include a common wire and a plurality of hot wires. Each hot wire is coupled to a corresponding valve, while the common wire is coupled to all of the valves by the junction unit. The junction unit utilizes resilient blocking members with frangible portions that block unused wire receptacles and can be removed to provide watertight access to the remaining wire receptacles. The junction unit is fixed in place via an anchoring mechanism such as a pipe clip or stake.